1. Field of the Invention
The present invention relates to a dartboard assembly and more particularly to a dartboard having automatic score capability.
2. Description of Related Art
With reference to FIG. 9, a prior art of automatic score dartboard assembly (50) has a dartboard (51), three light sources (52a, 52b, 52c) and three angle sensors (53a, 53b, 53c). The dartboard (51) has a front face (not numbered) and multiple segments (not numbered) in a circular scoring area (not numbered) on the front face. An equilateral triangle (A-B-C) is circumscribed tangentially on the scoring area of the dartboard (51) and has three vertices (A, B, C) coplanar with the face of the dartboard (51) and three sides (A-B, B-C, C-A) of equal length. The angle sensors (53a, 53b, 53c) are mounted respectively at corresponding vertices (A, B, C) of the equilateral triangle. The three light sources (52a, 52b, 52c) are mounted around the dartboard (51) between and coplanar with the vertices (A, B, C) and correspond respectively to the angle sensors (53a, 53b, 53c). For example, the light source (52a) between vertices B and C is opposite to the angle sensor (53a) at vertex A.
Since the light sources (52a, 52b, 52c) and the angle sensors (53a, 53b, 53c) are coplanar with the face of the dartboard (51), a dart (54) embedded in the face of the dartboard (51) will cast a shadow on at least one of the angle sensor (53a, 53b, 53c). By detecting the light emitting from which corresponding position on the light source (52a, 52b, 52c) was blocked, one can determine the position of a dart (54) embedded in the face of the dartboard (51). When any two angle sensors (53a and 53b, 53b and 53c, 53a and 53c) detect a dart (54) embedded in the face of the dartboard (51) and measure the angle to the dart (54) from each angle sensor, The angles and the known length of the sides (A-B, B-C, C-A) are used to calculate the exact position of the dart (54) on the face of the dartboard (51). Then the score of the dart (54) will be calculated.
Furthermore, this prior art of the dartboard assembly (50) often uses more than three angle sensors (53a, 53b, 53c) to calculate the scores of many darts (54) simultaneously embedded in the face of the dartboard (51).
To increase the accuracy of the angle sensor (53a, 53b, 53c), each angle sensor (53a, 53b, 53c) is composed of a charge capacitor device (CCD) and a lens (not shown), so the angle sensors (53a, 53b, 53c) of the conventional dartboard (51) are not cheap. Moreover, the alignment between the light sources (52a, 52b, 52c) and the corresponding angel sensors (53a, 53b, 53c) are critical to the accuracy of position determination, yet to achieve an exact alignment is a difficult process.
To overcome the shortcomings, the present invention provides an automatic score dartboard assembly to mitigate or obviate the aforementioned problems.